Search Results (564)

Flowering is a key agronomic trait that directly influences the yield of the tea-oil tree (Camellia oleifera). Floral initiation, which precedes flower bud differentiation, represents a critical developmental stage affecting the flowering outcomes. However, the molecular mechanisms underlying floral initiation in C. oleifera remain poorly understood. In this study, buds from five key developmental stages of a 12-year-old C. oleifera cultivar ‘changlin53’ were collected as experimental samples. Scanning electron microscopy was employed to identify the stage of floral initiation. UPLC-MS/MS was used to analyze endogenous gibberellin (GA) concentrations, while transcriptomic analysis was performed to reveal the underlying transcriptional regulatory network. Six GA types were detected during floral initiation and petal development. GA₄ was exclusively detected at the sprouting stage (BII), while GA₃ was present in all samples but was significantly lower in BII and the flower bud primordium formation stage (BIII) than in the other samples. A total of 64 differentially expressed genes were concurrently enriched in flower development, reproductive shoot system development, and shoot system development. Weighted gene co-expression network analysis (WGCNA) identified eight specific modules significantly associated with different developmental stages. The magenta module, containing Unigene0084708 (CoFT) and Unigene0037067 (CoLEAFY), emerged as a key regulatory module driving floral initiation. Additionally, GA20OX1 and GA2OX8 were identified as candidate genes involved in GA-mediated regulation of floral initiation. Based on morphological and transcriptomic analyses, we conclude that floral initiation of C. oleifera is a continuous regulatory process governed by multiple genes, with the FT-LFY module playing a central role in the transition from apical meristem to floral meristem. Full article

As a plant-specific peroxidase family, class III peroxidase (PRX) plays an important role in plant growth, development, and stress response. In this study, a preliminary functional analysis of CqPRX9L1 was conducted. Bioinformatics analysis revealed that CqPRX9L1 encodes a 349-amino acid protein belonging to the plant-peroxidase-like superfamily, featuring a transmembrane domain and cytoplasmic localization. The promoter region of CqPRX9L1 harbors various cis-acting elements associated with stress responses, hormone signaling, light regulation, and meristem-specific expression. The tissue-specific expression pattern of the CqPRX9L1 gene and its characteristics in response to different stresses were explored using subcellular localization, quantitative real-time PCR (qRT-PCR), and heterologous transformation into Arabidopsis thaliana. The results showed that CqPRX9L1, with a transmembrane structure, was localized in the cytoplasm, which encodes 349 amino acids and belongs to the plant-peroxisome-like superfamily. The promoter region contains stress-response elements, hormone-response elements, light-response elements, and meristem expression-related elements. The expression of CqPRX9L1 was relatively higher in ears and roots at the panicle stage than in stems and leaves. CqPRX9L1 showed a dynamic expression pattern of first decreasing and then increasing under abiotic stresses such as 15% PEG 6000, low temperature, and salt damage, with differences in response time and degree. CqPRX9L1 plays an important role in response to abiotic stress by affecting the activity of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD), as well as the synthesis and decomposition of proline (Pro). CqPRX9L1 also affects plant bolting and flowering by regulating key flowering genes (such as FT and AP1) and gibberellin (GA)-related pathways. The results establish a foundation for revealing the functions and molecular mechanisms of the CqPRX9L1 gene. Full article

Background: Bambusaoldhamii is an important economic bamboo species. However, flowering occurred after its introduction and cultivation, resulting in damage to the economy of bamboo forests. Currently, the molecular mechanism of flowering induced by introduction stress is still unclear. This study systematically explored the key genes and regulatory pathways of flowering in Bambusaoldhamii under introduction stress through field experiments combined with transcriptome sequencing and weighted gene co-expression network analysis (WGCNA), with the aim of providing a basis for flower-resistant cultivation and molecular breeding of bamboo. Results: The study conducted transcriptome sequencing on flowering and non-flowering Bambusaoldhamii bamboo introduced from Youxi, Fujian Province for 2 years, constructed a reference transcriptome containing 213,747 Unigenes, and screened out 36,800–42,980 significantly differentially expressed genes (FDR < 0.05). The results indicated that the photosensitive gene CRY and the temperature response gene COR413-PM were significantly upregulated in the flowering group; the expression level of the heavy metal detoxification gene MT3 increased by 27.77 times, combined with the upregulation of the symbiotic signaling gene NIN. WGCNA analysis showed that the expression level of the flower meristem determination gene AP1/CAL/FUL in the flowering group was 90.38 times that of the control group. Moreover, its expression is regulated by the cascade synergy of CRY-HRE/RAP2-12-COR413-PM signals. Conclusions: This study clarifies for the first time that the stress of introducing Bambusaoldhamii species activates the triad pathways of photo-temperature signal perception (CRY/COR413-PM), heavy metal detoxification (MT3), and symbiotic regulation (NIN), collaboratively driving the AP1/CAL/FUL gene expression network and ultimately triggering the flowering process. Full article

Caffeic acid-O-methyltransferase (COMT) is a key enzyme in lignin synthesis and secondary metabolism in plants, and it participates in the regulation of plant growth and development as well as plants’ stress response. To further investigate the function of COMT in grapevine, a total of 124 COMT family genes were identified from three Vitis species in this study, namely Pinot noir (Vitis vinifera L.), Vitis amurensis, and Vitis riparia. The amino acid sequence encoded by these genes ranged from 55 to 1422 aa, and their molecular mass ranged from 6640.82 to 77,034.43 Da. Subcellular localization prediction inferred that they were mainly located in the plasma membrane and cytoplasm. The prediction of secondary structures showed that α-helix and irregular coiled-coil were primary structural elements. These genes were unevenly distributed across 10 different chromosomes, respectively. Phylogenetic tree analysis of the amino acid sequences of VvCOMT, VaCOMT, VrCOMT, and AtCOMT proteins showed that they were closely related and were divided into four subgroups. The motif distribution was similar among the cluster genes, and the gene sequence was notably conserved. The 124 members of the COMT gene family possessed a variable number of exons, ranging from 2 to 13. The promoter region of all of these COMTs genes contained multiple cis-acting elements related to hormones (e.g., ABA, IAA, MeJA, GA, and SA), growth and development (e.g., endosperm, circadian, meristem, light response), and various stress responses (e.g., drought, low temperature, wounding, anaerobic, defense, and stress). The intraspecies collinearity analysis suggested that there were one pair, three pairs, and six pairs of collinear genes in Va, Pinot noir, and Vr, respectively, and that tandem duplication contributed more to the expansion of these gene family members. In addition, interspecific collinearity revealed that the VvCOMTs had the strongest homology with the VaCOMTs, followed by the VrCOMTs, and the weakest homology with the AtCOMTs. The expression patterns of different tissues and organs at different developmental stages indicated that the VvCOMT genes had obvious tissue expression specificity. The majority of VvCOMT genes were only expressed at higher levels in certain tissues. Furthermore, we screened 13 VvCOMT genes to conduct qRT-PCR verification according to the transcriptome data of VvCOMTs under abiotic stresses (NaCl, PEG, and cold). The results confirmed that these genes were involved in the responses to NaCl, PEG, and cold stress. This study lays a foundation for the exploration of the function of the COMT genes, and is of great importance for the genetic improvement of abiotic stress resistance in grapes. Full article

Vanillin, the principal aromatic compound in vanilla, is primarily derived from mature pods of vanilla (Vanilla planifolia Andrews). Although the biosynthetic pathway of vanillin has been progressively elucidated, the specific key enzymes and transcription factors (TFs) governing vanillin biosynthesis require further comprehensive investigation via combining transcriptomic and metabolomic analysis. For this study, V. planifolia (higher vanillin producer) and V. imperialis (lower vanillin producer) were selected. Time-series metabolomics analysis revealed 160–220 days after pollination (DAPs) as the critical phase for vanillin biosynthesis. Combined time-series transcriptome analysis revealed 984 upregulated differentially expressed genes (DEGs) in key periods, 2058 genes with temporal expression, and 4326 module genes through weighted gene co-expression network analysis (WGCNA), revealing six major classes of TFs: No Apical Meristem (NAC), Myb, WRKY, FLOWERING PROMOTING FACTOR 1-like (FPFL), DOF, and PLATZ. These TFs display strong regulatory relationships with the expression of key enzymatic genes, including P450s, COMT, and 4CL. The NAC TF family emerged as central regulators in this network, with NAC-2 (HPP92_014056) and NAC-3 (HPP92_012558) identified as key hub genes within the vanillin biosynthetic gene co-expression network. The findings of this study provide a theoretical foundation and potential target genes for enhancing vanillin production through genetic and metabolic engineering approaches, offering new opportunities for sustainable development in the vanilla industry and related applications. Full article

Polyamine oxidase (PAO) is an important enzyme that functions in the catabolism of polyamines. While plant PAOs have been studied in several species, there is a lack of research on this gene family in soybean (Glycine max L.), one of the major food crops worldwide. Here, a genome-wide analysis identified 16 GmPAOs from the soybean genome, which were unevenly distributed in nine soybean chromosomes and were then phylogenetically classified into three groups. Collinearity analysis identified 17 duplicated gene pairs from the GmPAO family, and their Ka/Ks values were all less than one, indicating that the GmPAO family has undergone purifying selection during evolution. Analyses of the conserved motif and gene structure revealed the sequence differences among the GmPAOs of the three groups, suggestive of their functional differentiation. Additionally, the prediction of the secondary and tertiary structure of the GmPAOs provided a further basis for revealing their biological functions. A number of cis-acting elements relevant to development, phytohormone, and stress response were discovered in the promoter regions of the GmPAOs, which might be responsible for their functional diversities. Expression pattern analysis indicated that more than half of the GmPAOs showed preference in flower, two showed specificity in stem and shoot apical meristem, whereas four were barely expressed in all samples. Expression profiling of the GmPAOs also revealed that they were involved in the response to abiotic stresses, including cold, drought, and especially submergence stress. All these results lay an important foundation for further characterizing the functional roles of GmPAOs in soybean development and response to abiotic stresses. Full article

Background: The flowering transition is a critical process determining the onset of reproductive development and fruit production. The molecular mechanisms underlying this process in coconuts are poorly understood; however, recent studies have identified CnHd3a as a potential regulator of the floral transition in coconuts. Methods: In this study, we characterized the molecular structure of CnHd3a and analyzed its alternative splicing forms in tall and dwarf varieties of coconut palms during the flowering transition. We used qRT-PCR to measure the expression levels of CnHd3a at different developmental stages. Results: CnHd3a was expressed in leaves and the shoot apical meristem (SAM) during the flowering transition in both coconut varieties and flower tissues during flower development. Interestingly, the expression levels of complex isoforms of CnHd3a were higher in the leaves of dwarf coconuts than in those of tall coconuts, suggesting their involvement in shortening the vegetative growth phase of dwarf coconuts. The gene structure of CnHd3a was found to be conserved across different plant species, indicating the evolutionary conservation of the floral transition process. Conclusions: Our findings provide insight into the molecular mechanisms underlying the floral transition and flower development processes in coconut palm. The tissue-specific expression patterns of CnHd3a isoforms show their potential roles in growth and development. Further investigations focusing on the functional characterization of CnHd3a isoforms will have practical implications for coconut breeding and cultivation strategies. Full article

Plant-specific WUSCHEL (WUS)-related homeobox (WOX) family of transcription factors are involved in apical meristem maintenance, embryogenesis, lateral organ development, and hormone signaling. Among the members of this family, WOX1 is known to play essential roles in many species. However, the function of the peony ‘Feng Dan’ (Paeonia ostii L.) WOX1 (PoWOX1) remains unknown. The initial bioinformatic analysis revealed that PoWOX1 belongs to the modern clade of the WOX gene family and has a highly conserved homeodomain (HD), the WUS motif, the STF-box, and the MAEWEST/WOX4-box. Subsequent heterologous overexpression in Arabidopsis thaliana revealed that PoWOX1 promotes root growth, early shoot initiation, and flowering. The root vascular tissues, especially the arrangement and size of xylem cells, were different between the PoWOX1-overexpressing transgenics and the wild-type plants, and the pericycle cells adjacent to the xylem divided more easily in the transgenics than in the wild type. Furthermore, under in vitro conditions, the transgenic leaf explants exhibited more callus induction and differentiation than the wild-type leaf explants. Thus, the study’s findings provide novel insights into the role of PoWOX1 in promoting root development and callus tissue induction and differentiation, serving as a reference for developing an efficient regeneration system for the peony. Full article

Auxins play a critical role in establishing the embryo axis and embryonic pattern. Our study aimed to determine the developmental stage of 21-day old oat (Avena sativa L.) haploid embryos, obtained by distant crossing with maize, and examined oat zygotic embryos at different developmental stages for their levels of endogenous indole-3-acetic acid (IAA), its metabolites, and IAA localization. The content of auxin metabolites was determined by HPLC-MS/MS, while IAA visualization in embryos was performed by immunohistochemistry and observed under confocal microscopy. We found that 21-day-old haploid embryos contained half the IAA concentration of age-matched zygotic embryos. Simultaneously, the total conjugated auxins (IAA-Asp, IAA-Glu, meIAA) were higher than in zygotic embryos, regardless of their age. Immunolocalization revealed IAA accumulation in embryos aligned with regions of tissue differentiation (e.g., shoot apical meristem, radicle primordium, and coleptile). We conclude that limited morphogenetic progression, evidenced by microscopic sections accompanied by changes in IAA content and distribution in haploid embryos, indicates a developmental stage earlier than the coleoptilar stage of zygotic embryos which occurs 9 days after pollination. Our findings may be useful in embryo rescue techniques, suggesting modulation of auxin concentration in in vitro culture. Full article

Triadica sebifera, an economically and medicinally valuable tree species native to China, was investigated for its in vitro regeneration potential using leaf explants from nodal cuttings of young stems and sprouts. This study evaluated the effects of basal media, plant growth regulators (PGRs), explant sources, and incision methods on adventitious shoot induction, supplemented by histological analysis. The highest shoot regeneration frequency (98.89%) and maximum shoot number (72) were achieved via direct organogenesis using sucker-derived nodal cuttings cultured on MS medium with 2 mg/L 6- benzyladenine (6-BA), 0.3 mg/L kinetin (KT), and 0.2 mg/L α-naphthaleneacetic acid (NAA). Under identical conditions, branch-derived explants showed lower regeneration (84.44%, 64 shoots). Transverse midvein incision proved most effective, with sucker-derived leaves exhibiting superior regeneration. Shoots elongated completely (100%) on Murashige and Skoog (MS) medium containing 0.3 mg/L 6-BA, 0.03 mg/L NAA, and activated charcoal. Rooting was optimal on MS medium with 0.3 mg/L indole-3-butyric acid (IBA), yielding a 98% acclimatization survival rate. Histological analysis revealed de novo meristem formation from parenchyma cells, confirming direct organogenesis without callus intermediation, further validating the enhanced regenerative capacity of sprout-derived explants. This efficient in vitro regeneration system provides a foundation for large-scale propagation and germplasm conservation of T. sebifera, while offering insights for woody plant regeneration studies. Full article

Viral infections in stone fruit crops cause substantial economic losses across all sectors of production. Despite their significance, viruses affecting stone fruits remain under-investigated in Kazakhstan. Among these, plum pox virus (PPV, genus Potyvirus, family Potyviridae), commonly known as Sharka, is the most critical viral pathogen worldwide, severely threatening the sustainable cultivation of stone fruits and posing risks to food security. This study aimed to evaluate virus management strategies in stone fruit crops to facilitate the production of healthy planting material from valuable genotypes. Field surveys were conducted in plum and apricot orchards located in the Almaty region (Southeast Kazakhstan) and the Saryagash region (Southern Kazakhstan). Plant samples were tested for the presence of the following viruses: apple chlorotic leaf spot virus (ACLSV), apple mosaic virus (ApMV), PPV, prune dwarf virus (PDV), prunus necrotic ringspot virus (PNRSV), cherry green ring mottle virus (CGRMV), and myrobalan latent ringspot virus (MLRSV). Real-time RT-PCR diagnostics confirmed the presence of PPV in the ‘Stanley’ and ‘Ansar’ cultivars and Prunus armeniaca genotypes, while both PPV and ACLSV were detected in the ‘Ayana’ variety. Chemotherapy (Ribavirin), thermotherapy, cryotherapy, and shoot apical meristem (SAM) culture, both individually and in combination, were used to eliminate viruses and regenerate virus-free plants. Successful virus eradication was achieved for PPV and ACLSV. However, the ‘Stanley’ and ‘Ansar’ cultivars did not survive the treatment process, likely due to high thermo- or cryo-sensitivity. As a result of this research, an in vitro collection of virus-free plants was established, comprising eight rootstocks, six plum cultivars, and three apricot genotypes. Full article

Cotton exhibits indeterminate growth potential at its apical meristem. In field cultivation, it is often necessary to restrict plant height by the foliar application of plant growth regulators or artificial topping. The genetic engineering of cotton architecture offers an efficient, environmentally friendly, and low-cost alternative to current field management. Our study aimed to improve the plant architecture of transgenic cotton by the suppression of GhSP, a key flowering repressor, via the RNA interference method. Sixteen independent transgenic lines were generated and classified as mildly, moderately, and severely suppressed, according to GhSP expression levels. Field evaluation revealed the dose-dependent effects of GhSP silencing on plant height. The mildly suppressed line GhSPi-#5 exhibited a semi-dwarf phenotype of approximately 70~100 cm in height. Negative phenotypes, including excessive dwarf plant architecture and inferior fiber quality and yield traits, were observed in severely GhSP-suppressed transgenic lines. Notably, the mild silencing of GhSP in GhSPi-#5 did not negatively affect leaf and flower organ growth, pollen fertility, major agronomic traits, or fiber quality compared with the wild type. These observations demonstrate the feasibility of manipulating the architecture of transgenic cotton via GhSP silencing. Full article

Tree peony is well-known for its ornamental value, medicine function, oil, and edible use. However, the difficulty in propagating tree peony impedes its cultivation and industrial advancement. Softwood cutting is an effective method to promote the propagation of tree peony. This research investigated the effects of several factors (cultivar, cutting phenological stage, auxin type, polyamine, and substrate) on the rooting of softwood cutting in tree peony. The results showed that rooting ability varied with cultivars and cutting phenological stages, with the highest rooting rates being for ‘High noon’ and ‘Jinghua Qingxue’ during the vigorous growth stage, reaching 50% and 53.33%, respectively. IBA 2000 mg·L⁻¹ was optimal for rooting in ‘High noon’ cuttings, with the maximum root number (5.67) and root length (6.3 cm). Putrescine of 1.0 mM could significantly improve the rooting rate and rooting quality of ‘Jinghua Qingxue’ cuttings, which had the highest rooting rate of 54.17% in the cocopeat/perlite substrate (v:v 1:1). Anatomical observation showed that most adventitious roots were generated from callus meristem nodules differentiated from cortical parenchyma cells while a few came from stem bark, as well as integrated root induction. This study is an innovation in and supplement to tree peony propagation research, and a propagation protocol was primarily established for softwood cuttings in tree peony. Full article

The plant hormones cytokinins are a class of heterogeneous active compounds that control multiple aspects of development and physiology. Among cytokinins, trans-zeatin (tZ), the most abundant cytokinin, has been extensively studied in relation to its effects on development, and it plays a key role in promoting cell differentiation. In analogy with tZ, here we demonstrate that dihydrozeatin (DHZ) controls (root) development by promoting cell differentiation. By means of pharmacological and genetic analysis, we demonstrate that DHZ is specifically and uniquely perceived by the histidine kinase (HK) receptor AHK3, and that this interaction is sufficient to promote cell differentiation in the root meristem via activation of the transcription factors ARABIDOPSIS RESPONSE REGULATOR 1, 12, and 11. We also show that DHZ and tZ activity might be conserved among plants. Our results support the idea that different types of cytokinins act via specific receptors to exert their roles and suggest new approaches to study their activity in differentiation. Full article

Highly differentiated tissues and organs play essential biological functions in multicellular organisms. Coordination of organ developmental process with tissue differentiation is necessary to achieve proper development of mature organs, but mechanisms for such coordination are not well understood. We used cotyledon margin cells from Arabidopsis plant as a new model system to investigate cell elongation and cell division during organ growth and found that margin cells endured a developmental phase transition from the “elongation” phase to the “elongation and division” phase at the early stage in germinating seedlings. We also discovered that the stem cell factors BARELY ANY MERISTEM 1 (BAM1) and WUSCHEL-related homeobox1 (WOX1) are involved in the regulation of margin cell developmental phase transition. Furthermore, exogenous auxin treatment (1 nanomolar,nM) promotes cell division, especially longitudinal cell division. This promotion of cell division did not occur in bam1 and wox1 mutants. Based on these findings, we hypothesized a new “moderate auxin concentration” model which emphasizes that a moderate auxin concentration is the key to triggering the developmental transition of meristematic cells. Full article